


all the things you left behind

by Oikawa_Fanclub



Category: Haikyuu!!
Genre: Alternate Universe - Assassins & Hitmen, Alternate Universe - Yakuza, Angst, Aobajousai, Character Death, Crying, Domestic Fluff, Dorks in Love, Fluff and Angst, HQ Rarepair Week, Haikyuu Angst Week 2020, Karasuno, Love, M/M, Made For Each Other, Marriage Proposal, Minor Character Death, Oisuga Week, Oneshot, Pain, Rarepair, Romance, Romantic Fluff, Sad Ending, Sleepy Cuddles, Volleyball Dorks in Love, Yakuza, a little bit of kurodai if you squint, laughing, mafia
Language: English
Status: Completed
Published: 2021-02-09
Updated: 2021-02-09
Packaged: 2021-03-15 07:41:38
Rating: Not Rated
Warnings: Major Character Death
Chapters: 1
Words: 4,474
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29310504
Author URL: https://archiveofourown.org/users/Oikawa_Fanclub/pseuds/Oikawa_Fanclub
Summary: Suga laughed to keep himself from crying when Tooru pulled out his own key from the inside of his shirt, and something deep inside of Suga (probably the hopeless romantic part) knew that this was the boy he wanted to marry.-Or-The things Suga kept after Oikawa left.
Relationships: Oikawa Tooru/Sugawara Koushi
Comments: 10
Kudos: 28





	all the things you left behind

\---

It was another successful mission. Another day that Suga drags himself home, blood splattered and exasperated beyond relief. His target had been a nuisance, but as always, he was able to get the job done. He saunters into his spacious apartment, one he picked for him and his lover, Oikawa. Suga traces the walls, decorated with pictures of them that Oikawa insisted they hang up. Obnoxious as always, Oikawa had also picked the color of the wall, a light teal blue.

He and Oikawa started dating their third year in college, right before Suga joined the Mafia. Oikawa had hated him then, still bitter over a highschool volleyball loss. Oikawa, spite driven, ignored him for most of first year- but then he had to share a dorm with him in second year, and it all spiraled from there.

\----

_“I can’t believe I hated you, Kou-chan,” Oikawa breathlessly remarks after their first kiss, in the bedroom doorway of their dorm. His hands gingerly cup his new boyfriend’s face, his cheeks three shades darker than before._

_“I can believe it.” Suga pokes at his side, making Oikawa squeal. “You are a petty person if I’ve ever seen one.”_

_Oikawa huffs and tackles Suga onto the bed, then the two play-wrestle not truly knowing why but only knowing that they each want to win. Suga’s boyish nature kicks in and he flips his legs up, caging Oikawa between his thighs. He smirks triumphantly, until Tooru lifts his hips and turns Suga over, their roles now switched. He shouldn't have let his guard down- Oikawa never gives up._

_The fact that Suga’s falling in love with him is a testament to that._

_“Well maybe I want to atone for my sin of hating such a pretty angel like you.” Oikawa purrs, taking a hold of Suga’s wrist and leaning close. He should be used to the brunette’s dramatics by now, but it still never fails to make him blush. As a trained assassin, Suga usually felt unease when in this position- but he never felt weary with Tooru. It’s an amazing feat within itself that he even trusts him at all- Tooru had to earn this level of intimacy._

_Sugawara Koushi is wrapped around Oikawa Tooru’s finger and he knows it._

_“By doing what?” Koushi tries to purr right back, but his voice wavers. Oikawa pulls him closer, till their lips brush, then Oikawa licks Suga’s bottom lip. Suga swallows a surprised moan._

_“I guess I’ll have to show you.”_

_Suga leans in, eyes closed, eagerly anticipating a steamy make-out session. His eyes snap open when he feels air on the receiving end of his kiss._

_“You're so naughty, Kou-chan!” Oikawa scolds, laughing as Suga whines below him._

_“How is it you always ruin my mood?” Suga rolls his eyes at Oikawa’s mock hurt. He began to shift when Oikawa’s grip tightened, forcing him to stay in place._

_“I wasn’t joking when I said I wanted to show you.” He says, suddenly serious. Suga loves when Oikawa changes in a blink of an eye, it should have set him on edge, but it’s honestly kind of sexy._

_He releases Suga and reaches in his back pocket, Suga’s mind racing with all the things it could be. Oikawa pulls out a key that looks extremely familiar, looped in a string, and Suga tilts his head in confusion._

_“Tooru, isn’t that-”_

_Oikawa rubs his neck sheepishly, and Suga found it really endearing how such a confident guy acted so bashful around him. “A copy of our dorm key, yes. I know it’s sappy as hell, but I really, really like you Koushi, and I just was thinking, If we ever get lost, this key will remind us where our home is.”_

_Suga laughs to keep himself from crying when Tooru pulls out his own key from the inside of his shirt, and something deep inside of Suga (probably the hopeless romantic part) knows that this is the boy he wants to marry._

\----

Suga touches the key on his chest, letting his hand feel the cool metal rise and fall against him. Not once has he taken it off since Tooru gave it to him.

Suga slumps over the couch, feeling exhausted. He forgot to pick up groceries, one of the many things he is constantly forgetting to do now. He smiles at the thought of how Tooru would scold him for not being responsible, but Suga can’t help it. He feels all too tired these days, so now Daichi- his best friend and skilled mafia combatant- would come over to drop off the groceries while chastising Suga’s lack of food consumption.

\---

_“Tooru, you menace, I told you to get strawberry cream cheese!” Suga shrieks at the boy while looking like the plain cream cheese personally wronged him._

_“But Kou-chan,” Oikawa whines scrunching his nose, “I hate that kind.”_

_“Maybe the world doesn’t revolve around you.” Suga rolls his eyes, unloading the produce from the bag._

_“It doesn't?” Oikawa laughs and kisses Suga’s forehead, then flops down on the couch. Oikawa always picks up the groceries because Suga is always busy running deals with the cover up of his work as a “professor”._

_They had just settled into their new penthouse, after college, and are still getting used to their nice, spacious complex. When Oikawa asked how Suga could afford it (Suga surprised Oikawa with the apartment, the taller astonished and slightly angry that Suga paid for it all by himself), he just simply told him he got a raise- which is partly true as he’s rising in rank in the Mafia. Oikawa is an astrophysicist, and good at what he does, which gains him six figures all on his own._

_They are filthy rich and they are happy._

\---

Suga had to throw out the plain cream cheese from Tooru's most recent grocery run. It had gone bad. 

He wills himself off the couch and makes his way into his office. Being a rising officer in the mafia isn’t an easy job, and it isn’t his favorite, but it had provided a great life for him and Tooru, and frankly, that’s what they had deserved. He stares at the dark mahogany wood, remembering the excitement that Tooru held when they walked around the furniture store. Tooru told Koushi that he would look sexy sitting behind a polished desk, and Suga took his word for it. 

He traces the bumps, dents, and scratches on the woodwork where Tooru and him got a little too heated in arguments or makeout sessions. Suga sits behind his desk, eyeing a broken teacup that he stored in a plastic bag as he did so.

\---

_“Kou-chan. What’s going on, there’s something that you aren't telling me.” Oikawa stands in the doorway of Suga’s office, sipping from his china teacup, one with an intricate sky blue design. He had caught Suga doing mafia work, and grown highly suspicious since. Suga cursed Oikawa’s observant eyes._

_“If I tell you, I’d have to kill you.” Suga is only half joking._

_“Spit it out, Koushi, I hate when you keep secrets from me.” Tooru pouts, letting his arms cross but never once tipping the teacup which is steady in his hands. Suga hates keeping secrets from Oikawa too, but this one is to keep him safe. He figures he’d have to tell him sooner or later though, and now is never a better time. He’d have to take some necessary precautions, but it’s worth telling the truth to the love of his life._

_“I’m in the mafia.”_

_The next thing Koshi hears is the porcelain teacup smashing into a million pieces._

_“Tooru, your cup-”_

_“What the fuck Koushi? This is no time for a joke,” Oikawa breaths harsly, his tone betraying his words. He believes Suga. Oikawa must've had this hunch for a while, but hearing it from his lovers lips has to be an entirely different thing._

_“Tooru, I can explain-”_

_“I’m dating the fucking mafia.” He turns around and storms out of the doorway, repeating himself like he hadn’t said it the first time._

_Oikawa grabs his jacket and slams the door to the apartment. Suga lets him. It’s a lot to learn that your boyfriend is in the mafia. If Oikawa wants to come back, he will. It still didn’t stop Suga from crying that night._

_Two days later, when Suga wakes up, he finds Oikawa splayed out on their couch. He had made his decision, and Suga couldn’t have been happier._

\----

Suga doesn’t know why he kept that stupid broken cup. Maybe because it was Tooru’s favorite. 

He finishes up his reports, filing a job that had been carried out that week. Suga has a notorious record, he is incredibly skilled in what he does. He can fight anyone, although he’s primarily used for infiltration and assasination. Quick decisions and light on his feet, he’s perfect for espionage. Tooru had always said Suga’s niftiness scared him, and Suga often used his stealth training to prank the brunette. 

Come to think of it, Tooru has always been supportive of him, and incredibly understanding, even when things got weird.

\---

_“I don’t like you killing people.” Tooru speaks on a cool summer evening, head resting in Suga’s lap. They are at a park in Miyagi, where they grew up. It’s their favorite place. “Seeing you with other people’s blood on your clothes- though I guess that’s better than another person’s cologne-” He chuckles, but it’s forced. “Koushi, It’s unnerving.”_

_“I know, Tooru.” Suga murmurs softly, gently carding his fingers through Tooru’s hair. He hums. Suga had been on a mission earlier, and broke his right wrist, along with other bruises and scratches. He made the mistake of coming home to Oikawa right after and will never forget the absolute horror and worry of the brunette as he fretted over him, tears fresh in his eyes, along with sobs of “I don't want to lose you.” Suga despised the sight and vowed that he would get patched up at HQ from then on. After he had calmed down, Tooru asked why Suga was in the Mafia and why he had to stay._

_Suga answered both. Tooru, reluctantly, understood. Neither have brought it up since._

_“But I also want you to make it back every night, whatever it takes.” Oikawa sits up to look into Suga’s eyes, making sure his words are getting to his boyfriend._

_“How selfish of you,” Suga teases, and Oikawa huffs._

_“You knew what you were getting into. I’m a selfish brat, especially when it comes to you, so you better come home to me no matter what.”_

_“Of course.”_

_Tooru, satisfied, drops back into his lap._

\----

Suga hasn’t been to their spot in ages. 

He sighs, and gets up from his desk. He’ll probably be assigned a job tomorrow, so he should get some rest. He walks slowly into his room, and flops down into his bed, wanting nothing more than to cover himself up with sheets and sleep.

He nuzzles his head into the mattress, letting the soft lavender sheets comfort him. Oikawa had picked them out for the Master Suite- “Only the best for my Kou-chan!”- but Koshi always liked to complain about the clash of the purple with the soft green of their bedroom walls. They had a whole argument on color theory once, it was kind of ridiculous. Suga longs for that banter again.

He misses being able to curl up into Oikawa’s arms at the end of the day. To be held like he is important and told that everything is going to be okay- even if it was a blatant white lie.

\----

_“You're looking awfully tired today,” Oikawa chirps when Suga flops down on the bed next to his shirtless boyfriend. Tooru looks away from his book to the exasperated Suga whose limbs are all sprawled out._

_“Work today was horrible,” Suga sighs, like he was talking about a regular job._

_“Wanna talk about it?” Oikawa inquires, running his hand through Suga’s hair the way he knows his boyfriend likes it. Suga would love to in depth, but most of the details are classified, so he went for the general summary._

_“Couple of close calls, it was fine, but before I dropped him the target started to put up a fight.” Suga groans, as if just mentioning it brings the bruise on his cheek to flaming pain again. Tooru laughs, now used to Suga casually talking about murder. “It was ridiculous, he totally saw me coming- but I was dead quiet so how he knew is anyone’s guess. Someone that douchey should not be allowed to put up such a good fight.”_

_Oikawa ruffles Suga’s hair and Suga squawks, but doesn't do much else. As Suga watches Oikawa laugh on their king sized bed, he thinks he doesn’t mind the clash of the lavender sheets as much when Tooru’s abs look so good between them. He’s ready to pounce to get some much needed action, then:_

_“Good thing my sugar is amazing at what he does.” Oikawa remarks, completely genuine and Suga beams- then attacks him with a sensual kiss._

\---

“Sugar.” To think. Oikawa actually thought that of him. Oikawa actually saw him as someone good, someone sweet. Oh, how Suga wants to believe him.

Maybe he thought that way because Suga was a relentless gifter. He loved spoiling Oikawa, not because he wanted to woo him, but simply because he knew Oikawa deserved it. Oikawa had earned everything Suga gave him, including his heart.

He told Oikawa multiple times that he didn’t do this because he was a good person, but Oikawa always insisted that he was, then went out and spoiled Suga right back. Eventually Suga let it go, arguing with Oikawa would be futile. If Tooru believed something, no one could ever waver him from it. 

Suga snaps out of his thoughts and turns his gaze to Tooru’s faded red stained jacket in their closet. He had washed it mildly, but hadn’t bothered to try to get rid of the remnants of the bodily fluid.

Or at least that’s what he told Daichi. In reality, he kept it as a reminder. Tooru’s blood is on his hands.

\---

_“What do you think?” Oikawa grins, flaunting his new Air-Forces with a stupid alien design._

_“You look cute, Tooru, though aren’t you ever going to get out of the alien phase?” Suga smirks when he gets his desired reaction, an offended gasp from his new fiancee. Tooru had just proposed to him two weeks ago, in Greece._

_“Aliens are for everyone, Kou-chan, don’t insult me. Plus, look!” Tooru points to his favorite jean jacket that Suga got him for his birthday. He grins like a kid on christmas when he shows Koushi the iron-on Alien patch on the front of his jacket that reads “I believe”._

_“You're such a nerd, I don’t even know how I deal with you.” Suga quips and Oikawa scowls, grabbing his sunglasses off the island. Suga comes up to him and presses a kiss to his cheek, then Oikawa grabs Suga’s face and aligns their lips. Suga smiles into it, closing his eyes and parting his mouth. He feels Oikawa’s tongue slip inside- he wants to cherish their tender kiss but his mischievous nature gets the better of him- and he bites down on Oikawa’s tongue, not enough to hurt him. Oikawa squawks anyway._

_“You're absolutely feral, Kou-chan!”_

_“You love it.”_

_Suga watches Oikawa pout with the fondest smile. Oikawa moves away from him and stands in front of the window, letting the sun engulf his skin. He admires how Oikawa’s face lights up in the sun, his lashes catching the sunlight. He looks ethereal, so beautiful, a small smile gracing his lips. He’s too busy staring at his enchanting fiancee to notice the glint from the other building, and he hears too late the shattering sound of the window._

_In hindsight, he should have seen this coming. They are in a penthouse with a huge glass window, perfect for assasination. But no one has ever been dumb enough to mess with Suga or his syndacate- until now._

_A scream rips through Suga’s throat as he rushes to Oikawa’s crumpled body._

_“Fuck!” he screeches, pressing his hands to Oikawa’s open, messy wound. He glares out the hole in his apartment, frantically searching for the sniper. His eyes land on a blur of purple and red, and in an instant he knows this is Shiratorizawa’s doing._

_“Tooru, shit, please hold on, please,” Suga begs, tears flowing, yelling orders at their smart device to call 119. He cradles his bleeding lover, murmuring desperate pleas, letting blood leak into the crevices of his engagement ring._

_Suga finally registers that Tooru isn’t actually listening._

_Suga’s seen death. He’s been around it his whole life. He was 8 when his parents were murdered, 10 when the mafia took out his uncle, and 12 when his cousin got shot and he promised the Karasuno syndicate that he’d join them once he’s 20, if they would stop killing the people he loved. Karasuno recognized his natural skill and decided to hold his family's debt over Suga’s head, promising him that if he ever tried to leave, they’d kill him and everyone he cared about. He was adopted by a mafia officer, and 14 when he killed his first person. 18 when his body count reached 40. 19 when he fell in love with Oikawa. A year after that, he officially joined the syndicate with 60 assassinations and not one failure. He knows what it’s like to literally have other people’s blood on your hands. He knows what it’s like to watch the life drain out of an innocent person, just because luck had not been on their side. He knows, and he’s used to it._

_But watching Oikawa’s honey eyes fade into dark brown is harrowing. Suddenly, it feels like Suga is experiencing death for the first time all over again. A tsunami of emotions ambush him, a feeling that claws at his stomach, scratching and cracking his ribs. His insides collapse, his voice is hoarse and his hands tremble. It grips his brain and shakes, leaving Suga falling, spinning, spiraling into a void of devastation. His lungs clench, breath ragged and barely there. His heart is bursting with a pain Suga hadn’t felt in years._

_Gripping the love of his life’s limp body, He wails._

_It’s then Suga realizes that he is never going to have a happy ending, only a taste before it’s ripped away from him, a sniff of something that was never there. He was never going to marry Tooru. He was never going to have an apple pie life with a picket fence, 2.5 kids and a dog. He doesn’t deserve that. He is a man of many sins, and if there is one thing he definitely didn’t deserve, it was Tooru. Beautiful, smart, kind, patient, and unconditionally-loving Tooru. Suga’s guilt rips through his mind. He dragged Tooru into all this. Tooru should have ran the first chance he got. Instead he stayed, he made Suga hope, made him dream._

_It’s a dangerous thing, to make someone with no future believe that they have one._

\---

He had found the person who killed Tooru, the man with flaming red hair. It was revenge for Suga’s earlier assasination of Ushijima, the rival sniper’s lover. Suga tied him to a chair and ripped his skin open with a knife- then quite literally added salt to the wound. The man had screeched in pain and screamed at Suga to show mercy, but why would he? The man didn’t show any mercy to Tooru. Satisfied with his touture, Suga slit his throat and left him tied in the chair to rot.

He knew deep down Tooru would’ve disapproved of that, but he hadn’t cared. Tooru wasn't there anymore.

Suga had found himself trying to fill the hole with alcohol and violence. Much too often did Suga wake up on Dachi’s couch, a killer headache and pain medication left by Daichi’s boyfriend Kuroo. He’s also becoming more ruthless and cold, begging for missions where he could kill someone. Daichi and Kuroo try to help but can really only watch Suga’s descent, falling off the rails without Tooru to set him straight. 

A rug was pulled from under him, but instead of revealing a bare floor, there was a gaping hole- and it swallowed Suga. The life they had built, a life Suga was finally happy with, was ripped away by a tiny bullet.

Suga doesn’t realize he even grabbed it until his hot tears stain a dark blue in Tooru’s jean jacket. God, he misses him so much. It’s been a week since the shooting, and Suga is spiraling, slowly but sure. His masochism is no help, and he grips the jacket as if throttling it would bring Tooru back.

With the jacket clutched in his hands, Suga sits up- an abandoned silver band on his nightstand had twinkled and caught his eye- he reaches for it, then takes off his own.

\---

_“Tooru, since when did you become so slow?” Suga calls after his boyfriend, running along the beach. They’re on Navagio beach, in Greece, an impromptu trip stimming from Tooru’s complaints for stress relief. Suga surprised him with plane tickets, and the next week, they were at the Resort._

_“How about you slow down, Kou-chan, my god!” Oikawa screams at the boy, obviously frustrated that he can’t keep up with his nimble lover. Suga stops abruptly and laughs, giving Oikawa the opportunity to lift Suga up into his arms, spinning him around. After a breathless “Tooru!”, Oikawa gently puts him down, letting his hands settle on Suga’s hips._

_“Thank you for this, Koushi, really. Though I could’ve helped pay-”_

_“Don’t be silly, you already help pay the bills, and groceries, and that one time you got me a red mustang-”_

_“Kou-chan, we live together. Of course I pay bills and buy groceries. The car was a gift.” Tooru rolls his eyes, smile betraying his action. Suga just kisses his nose and laughs, looping his arms around Tooru’s neck. Suga takes the time to admire his lover’s face, to take in the soft curl of his lips and the chestnut hair that compliments his honey brown eyes. Gold flakes dance in his irises, both amused and smitten simultaneously. Suga loves that Oikawa feels comfortable enough to expose his usually well guarded emotions- He revels in the fact that he’s able to read Oikawa like a book._

_“In fact, Kou-chan, I have a surprise for you too.”_

_Suga’s heart quickens, reliving the thrill he always feels when Oikawa says those words. Oikawa lets go of Suga’s hips, the latter holding in a whine to protest the lack of warmth. Oikawa’s eyes flicker with mischief, and Suga shivers. Sure, Suga prides himself on being able to read his boyfriend, but he’s quickly reminded that he’s still unpredictable._

_“Close your eyes, sugar,” He softly commands and Suga listens, heart thumping in his throat. He puts his hands over his eyes, for good measure, and waits._

_He hears Oikawa shift and move in the sand, his anxiety climbing every second that passes. Just what did Tooru have? As a trained mafia member, he is versed in patience, but that doesn’t mean he has to like it._

_“Okay, open.”_

_Suga tears his hands away, eagerly looking for Tooru, to realize he’s on one knee below. He holds an open black box, and inside is a silver ring with an intricate design._

_“Koushi, I have known you since high school, and it’s not an exaggeration to say I hated you, Mr. Refreshing. But you taught me, better than anyone, to not judge a book by its cover. I’m glad I got over myself, because I got to know the most beautiful, kind, and special person I have ever had the privilege of loving. You have changed me for the better, and I hope to keep changing with you. Sugawara Koushi, the most important person in my life, will you marry me?”_

_Suga sobs, waterworks flowing hot and heavy down his cheek. He hears his heart in his ears and feels his arms shaking. He tries to respond, but his tears get caught in his throat. Tooru just stays there, patient, satisfied with Koushi’s reaction but waits for a verbal confirmation._

_“Don’t ask stupid questions,” Suga finally chokes out, like he had planned this all along. Oikawa just laughs. “Of course I’ll marry you, Tooru!”_

_He tackles Oikawa with a kiss, almost making the brunette drop the ring into the sand. They are laughing, and Suga notices Oikawa’s own tears rolling down his cheek. Suga puts his full weight on him, pinning Oikawa in the sand._

_“Let me put the ring on my fiancee,” Oikawa complains, and Suga snorts. He sits up and shifts onto Oikawa’s lap, letting Oikawa sit up as well._

_“Where’s your ring?” Suga pries, well aware that usually the only one who got a ring is the one being proposed to, but knowing Oikawa, he probably got one for himself. Oikawa smirks as he lifts his left hand, a silver band with the same intricate design fitted around his finger. Suga giggles at his soon-to-be husband’s smugness and asks: “What if I rejected you?”_

_“Nah, I knew you would never let all this goodness go,” Oikawa quips, and Suga snickers. He grabs Suga’s hand and slips the ring onto his fiancee’s slim finger, placing a kiss on his hand as he does so. It fits perfectly. For once in his life, Suga feels so right, like all the suffering and hardships were worth it because it all led up to this moment._

_High on his elation and too busy kissing Tooru, he doesn’t even feel the engravement on the inside of the ring until later._

\---

The two silver rings in his hand now feel like 100 pound weights.

Suga grips the metallic bands, tears starting to swell in his eyes. Suga rus his thumb on the engraving on the inside of his ring. 

“Forever and Always- Tooru”

A sob escapes his lips. Oikawa didn’t have anything in his ring at first, but Suga stole it one night to get an inside engraving of its own. One that made Oikawa squeal in delight when he saw the inside. A reminder of how happy Suga had been. Of how fleeting that happiness was. 

Oikawa is the first and hopefully the last person Suga will ever love. He now knows better than anyone that love only got you hurt- he doesn't think he could love anyone besides Oikawa anyway.

Even if Tooru isn’t here, Koushi intends to make good on the promise inside his ring.

“Always and Forever- Koushi”

\----

**Author's Note:**

> I hope you enjoyed! I've really wanted to write for Oisuga for a long time, so what better to do it with than my favorite Genre: Angst!! 
> 
> Don't be afraid to comment or interact with me! Much love - <3


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